DEAR SAM: We are planning to insulate our 70-year-old two-story house. There is little head room in the attic because of the shed-type roof. We had planned to have insulation blown in but none of the contractors has mentioned a vapor barrier. We have been told that painting the second floor ceilings would provide a vapor barrier. Is this true? We have not yet tackled the problem of the sidewalls, since the house has a stucco finish with wire mesh behind it, which is evidently difficult to cut through for blowing in insulation.
ANSWER: With very low eaves, insulation can be blown in. The most common insulation for the attic floor is mineral wool, such as fiberglass or rockwool. I trust that you have some roof vents, so moisure can escape. Two louvres in the gables (16 x 24 inches) would be preferable for cross-ventilation.
Although vapor barriers are necessary, it would be a more difficult job to install the six-inch bats with the attached vapor barriers. The lack of headroom near the eaves would require crawling on one's stomach or the use of extension rods to guide the bats into position. Also, six inches would not be as satisfactory as eight inches, which can be blown in easily. Latex paint on ceilings is a satisfactory substitute for paper-type vapor barriers.